Dye-receptive acrylonitrile polymers



Patented Mar. 2, 1954 PILYMERS George afnam fana Alfrei is. 1eme,

metten,

"hio, Sassigfnora L"by mesnef as'sgfnments, to The `YChemstrand Corporation, "al `Icorporationv of Delaware minier-ving. nppucaticniiuayee, 1.951, 'seria-'1nd 228,535

'This invention `vrelates lto 1 polymeric compositions *hav-ing unusual ber-:forming properties. More speccally, 'f;he"in'vent-ionfrela-te's to aory lonltrile polymers lcapable A'of being converted readily 24into Adyealole --general purpose bers.

iIt is vwell known that `polyacrylonitrile ifand various copolymers of 'acrylonitrile `and other dleiinic "monomers, -ca'n be I'spun into synthetic be'rs 'having iinusua'l physical 'proper-ties. Because polyacrylo'nitrile 'and many copolymers of acryldnitrile "are :almost :inert chemically, =con ventio'nal dyeing procedures are not universally iiseful Iin 4.their processing, vMany copolymersoi acrylontrile liave been prepared using Ias comjonomers `substances which have dye 'ainnity. Poiymersiof this-typeiarenotialways satisfactory, because ofthe-excessivecostfor c'olnonomers, and because the introduction fof the -comonomers often depreciatesl the desirable properties of the ultimate bers.

-One purpose -of this invention is -to provide new aoryl'o'nitrile `looiyrners which 'have Athe -usual physical ipr'operties of polyacrylonitrile, but which can easily loe 'Inade completely dye-receptive. A further purpose of this invention Jis to fp'rovide a simple, practicahle and 'inexpensive .-inethodof preparing-'dye-reoeptive acryIonitri-le fibers. Fui'- ther purposes of this invention will-hevev-iient from the v"description set @forth hereinafter.

-I-'n accordance with this Iilfiventior'l,'it -has been fo'nd that-acrylonitrile polymers having 'copolyrnerilzel therein alpha-chloroacrylic#derivatives orV fcontaining l'blended therewith vpolymers *of the alih'aedhloroacrylio derivatives, may 'be rendered dye-receptive by after-treatment with reagents which convert the chlorine fatom into an ionic chlorine radical. This invention contemplates usingconolymersof 8G or more percent-of acry lonitrile.A and `from two to 2G :per cent" of an alphadhloroaorylate derivative, for 4 Vexample alkyl alihaechloroacrylates, wherein the alkyl 'radical has up to four-carbon atoms, such as `methylalpha-=chloroacrylate, ethyl-alphaechloroacrylate,

p'rcpyiefaipna chiorcseryiete aiphgicmoroacryim iiitiile, and chloroacrylaniide. 'The loopolynie'rs offeeryiomtr-iiefancfthe aiphaehloroecryiic com*- pounols may, if desired, have copolymerized therewith other lolenic monomers -fo'r fthepurpose of further modifying the chemical Tandphysical properties of the ultimate ibe'is.

'Instead-oi lthe utilizing =of copolymers of -acrylonitrile andl Athe 4chloroaor-ylic 1derivati-'ves, lth'e two lcritical rnfionomers 'may each loe pre'sent iin d iilerentl polymers which are fblendedzphysically. This :procedure contemplates utilizing ias ithe spine-iper :polymer adyacente-ione 'or einem mers idf 9o L:sement 'orfimore ofh'aerylcnitrile and minor proportions of one or-mre other-imonlimers mopolyinerizable therewith, for example nyl acetate, styrene, ialpha#niethylstyrerie, "alkyl mie'ate's, eikyl romaines, -aikyi -acrylate-s, e'ikyi meth'ao'rylates, imetliaerylonitrile, vinyl chloride and vinylideneehloride. Thefprincipal polymer is 'ithen -'lolended with #minor proportionof a chlorin'eeoontai-n'irig Loopolyme'r fefr'o'm to 'no per ice'nt of Ithe feaidfhlozo'aoryli'c acid derivative,y and one or more merizable therewith, for eea-ampleviriyl aoetate, styrene, alp'hamethylsty'rne, l 'a`li :y`l inaletes, alle-y1 fumare/tes, alkyl 1aflaiiS,-`falkyl methane rylates, methacryloriitrile, vinyl fehl'oride #an-Ll vinylidene chloride.

l:Both the copo A'i:f1.'e1s etrid the blended ipolymers Will beCapalol-eo cn've'rsion-int'o @dye-receptive polymers by conversion-of the Cll'lrine atomin'bo an ionic chlorine radical, if a substantialpor tion of the childrine-lcontainingA cnioiind Aiis present. hasbeenifound-thatirom t'wb toli per L'cent1-of 'the total monomers present iiiipolfyrthe chlorine-containing monomer. It will be apparent that the quantity of eaohicopolymer blended will Iitle'ioencl u'pon the proportion of chlorineiciitaini-ng imorio'i'ner A'in the reactive copolymer #and ilthe proportion lshould be f so selected 'as -to 1ero-vide the reqisi-te two to 115 percentof'fthe total monomers in the form of-fthe chlorine-containing imonom'er.

y-In the practice of this invention, the 'copolymers -or blended polymers lare #reacted with. one

of 'a variety y-of agents of the f'griip Yof ammonia,l

amines, thioureas land 2-rneifoaptohenzothiaola which Will ooiffivrtthe "ohlorine-coifi-taiiilng lacrylic groups into ian ionic `form. Exam-ples `oi siiohfuseful reagents are ammonia, primary-secondary, 4or *tertiary amines, ithio'urea, valkyl thioureas, -2mercaptobenzothiazole, for 'other basic mercaptans, tris climethylamido) phospliite, or tris (diethylarnido) phosphite.

The copolymers and Ieach fof "the polymeric components of ithe 'blended 'polymers can :he prepared by anyo'f "the conventional polymerioation methods, including fmass, 'solntion 'andaquen ous l"dispel-'sion technici-ues. The aqueous 'dispersion or "emulsion procedures are generally preferred beaise they Aprovide convenient infine'- tr'ially practicable methods for .preparing high molecular =weight and physical properties. 1

The 'aqueousA 4dispersion -p'olymerizations `involi/e Ythe use fof' r'e'e radical da't'alysts` 'for expolymers o?.k luniform chemical ample, peroxides and azo compounds. The high acrylonitrile polymers preferably utilize watersoluble peroxides, such as the alkali metal or ammonium salts of persulfuri, perboric percarbonic or other peroxy acids.

The polymerization procedures may involve the use of emulsifying or dispersing agents. The high acrylonitrile fiber-forming polymers are readily formed in finely divided state with or without conventional dispersing agents, and when Such dispersing agents are used, only minor proportions, for example from 0.01 to 0.5 per cent based on the total monomers being polymerized, need be employed. The dispersing or emulsifying agents are compounds which have both hydrophobic and hydrophilic functions, for example, salts of long chain carboxylic acids and mixtures thereof as obtained by saponiiication of animal and vegetable fats, salts of sulfonated hydrocarbons, particularly the alkylbenzene sulfonates, salts of the dialkyl sulfosuccinates, and salts of the aldehyde condensed naphthalenesulfonic acids. In the preparation of copolymers of more than per cent of the alpha-chloroacrylic derivatives, the dispersing agents are frequently necessary, and the use of soap is preferred. Under the latter conditions a coagulating agent may be required to break the stable emulsion formed.

Although batch or continuous polymerization methods may be used, the preferred technique involves a semi-continuous procedure Where a predetermined quantity of monomer or mixture of comonomers is added gradually to a reactor charged with the aqueous medium and containing catalyst and other essential reaction components. If desired, the catalyst and dispersing agent, if one is used, may be added gradually to the reaction medium during the course of polymerization. By maintaining in the reactor approximately the same concentrations of catalysts and each of the monomers, a substantially uniform rate of reaction and a uniform desirable product are achieved. A constant temperature of reaction further contributes to the uniformity of reaction conditions and the properties of the polymer.

The reaction may be conducted in glass or glass-lined reactors provided with stirring or other agitation mechanism. The reactors should preferably be provided with reflux condensers and f means for adding the monomers and other reactants or reagents to the reactor, either at the beginning of the reaction or during the course of the polymerization. The polymers may be separated by conventional filtration apparatus, preceded by coagulation, ii necessary.

In the practice of this invention the chloroacrylic radical-containing polymers may be treated in solid phase or in solution in suitable solvents, for example, dimethylacetamide, dimethylformamide, butyrolactone and ethylene carbonate.

The solid polymer or the ber formed therefrom may be treated by a gaseous or a liquid reagent. The preferred process, however, involves the reaction between the reagent and the polymer in a liquid which is a solvent for both. The finished fiber may be treated as a continuous strand, in skeins, or in other packaged form, with gaseous reagent or with a liquid reagent or solution of any reagent to effect the desired conversion of the chlorine group to an ionic chlorine atom.

Under some circumstances some of the re-.

agents may induce cross-linking of the polymer which can interfere with the eicient spinning of the polymer into ber. Tertiary amines can be used in all of the described embodiments. The use of ammonia is of most value in the treatment of fibers. Primary and secondary amines frequently cause gelation when used in reactions involving polymer solutions of the compositions.

The polymers and solutions thereof are processed into fibers by conventional expedients and the details of such operation are not regarded as part of this invention.

Further details of the invention are set forth with respect to the following specific examples:

A mixture of 93.5 parts of acrylonitrile, 6.5 parts of alpha-chloroacrylonitrile which contained, in addition 0.2 part of tertiary-dodecylmercaptan was gradually added to 370 parts of water and 0.1 part Acto 450 (a mahogany soap prepared by the sulfonation of a hydrocarbon fraction and obtained as a by-product in the reiining of petroleum) in a glass reaction flask equipped with a condenser and stirrer over a period of two hours at C. During this period 0.5 part of potassium persulfate was added, dissolved in 30 parts of Water. After an additional reflux period of one-half hour the reaction mixture was steam-distilled to remove unreacted monomer, and the nely divided white copolymer was filtered, washed with water and dried. A 91.4 per cent conversion to a copolymer of 93.75 per cent aorylonitriie and 6.25 per cent alpha-chloroacrylonitrile was obtained. Fibers were obtained on spinning a 16 per cent solution in dirnethylacetamide into a mixture of 60 per cent di-` methylacetamide and 40 per cent water followedby Washing in water, and stretching 320 per cent in a steam atmosphere.

A portion of the copolymer solution in dimethylacetamide was mixed with trimethylamine in an amount equivalent to the alpha-chloroacrylonitrile in the polymer. Fibers were spun from the treated solution by the method described in the preceding paragraph.

Using dyebaths containing two per cent Wool Fast Scarlet dye and ten per cent sulfuric acid (based on the weight of fiber being treated) and 41 cc. of water per gram of fiber, the fibers were heated for one hour at the boiling temperature. It was found that the ber prepared from polymer which had been treated with trimethylaminewas completely dye-receptive, but that the ber from untreated polymer was nearly colorless after the same treatment.

Example 2 containing 0.1 gram of Wool Fast Scarlet dye,v 0.5 gram sulfuric acid and 205 cc. of water forproduced brilliant scarlet each gram ofvfilm, film.

The invention is defined by the following claims.

W hat we claim is:

1. A method of preparing a dye-receptive ac rylonitrile polymer which comprises contacting a polymer of from 20 to 98 parts of acrylonitrile and from 2 to 80 parts of a compound of the group consisting of alpha-chloroacrylonitrile.v

alpho-chloroacrylamide, and the alkyl esters of alpha-chloroacrylic acid wherein the alkyl radicals contain up to 4 carbon atoms, with a reagent selected from the group consisting of am* monia, amines, thioureas and Z-mercaptobenzothiazole.

2. The method dened in claim 1 wherein the compound is alpha-chloroacrylonitrile 3. The method as dened in claim 1 wherein the compound is alpha-chloroacrylamide.

4. The method as defined in claim 1 wherein the compound is methyl-alpha-chloroacrylate.

5. The method as deiined in claim 1 wherein the compound is ethyl-alpha-chloroacrylate- 6. The method as defined in claim 1 wherein the compound is propyl-alpha-chloroacrylate.

7. The method as defined in claim 1 wherein the reagent is a tertiary aliphatic amine.

8. The method as defined in claim 1 wherein the reagent is thiourea.

9. The method as dened in claim l wherein the 'reagent is tris (dimethylamido)phosphite.

10. The method as dened in claim 1 wherein the reagent is 2-mercaptobenzothiazole.

l1. A dye-receptive copolymer which comprises a salt prepared lby reacting a copolymer of from 20 to 98 percent of acrylonitrile and from 2 to 8O percent by weight of a compound o1" the group consisting of alpha-chloroacrylonitrile, alphaohloroacrylamide and the alkyl esters ci alphachloroacrylic acid wherein the alkyl radical contains up to 4 carbon atoms, with a reagent selected from the group consisting of ammonia, amines, thioureas, and 2-mercaptobenzothiazole 12. A dye-receptive copolymer which comprises a salt prepared by reacting a copolymer of from 20 to 98 percent of acrylonitrile and from 2 to 80 percent by weight of alpha-chloroacrylonitrile with trimethylamine.

13. A dye-receptive copolymerwhich comprises a salt prepared by reacting a copolymer of from 29 to 98 percent of acrylonitrile and from 2 to 80 percent 'by weight of alpha-chloroacrylonitrile with thiourea.

14. A dye-receptive copolymer which comprises a salt prepared by reacting a `copolymer of from 2 0 to 98 percent of acrylonitrile and from 2 to 80 percent by weight of lalpha-chloroacrylonitrile with tris (dimethylamido) phosphite.

15. A dye-receptive copolymer which comprises a salt prepared by reacting ya copolymer of from 20 to 98 percent of acrylonitrile and from 2 to 80 percent by weight of alpha-chloroacrylonitrile with tris (diethylamido) phosphite.

GEORGE E. HAM. ALFRED B. CRAIG.

References Cited in the le of this patent UNTED STATES PATENTS Number Name Date 2,384,889 Clifford et al. Sept. 18, 1945 2,436,926 Jacobson Mar. 2, 1948 2,497,526 Arnold Feb. 14, 1950 

11. A DYE-RECEPTIVE COPOLYMER WHICH COMPRISES A SALT PREPARED BY REACTING A COPOLYMER OF FROM 20 TO 98 PERCENT OF ACRYLONITRILE AND FROM 2 TO 80 PERCENT BY WEIGHT OF A COMPOUND OF THE GROUP CONSISTING OF ALPHA-CHLOROACRYLONITRILE, ALPHACHLOROACRYLAMIDE AND THE ALKYL ESTERS OF ALPHACHLOROACRYLIC ACID WHEREIN THE ALKYL RADICAL CONTAINS UP TO 4 CARBON ATOMS, WITH A REAGENT SELESTED FROM THE GROUP CONSISTING OF AMMONIA, AMINES, THIOUREAS, AND 2-MEREAPTOBENZOTHIAZOLE, 